From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- fs/btrfs/raid56.h | 291 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 291 insertions(+) create mode 100644 fs/btrfs/raid56.h (limited to 'fs/btrfs/raid56.h') diff --git a/fs/btrfs/raid56.h b/fs/btrfs/raid56.h new file mode 100644 index 000000000..854264819 --- /dev/null +++ b/fs/btrfs/raid56.h @@ -0,0 +1,291 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2012 Fusion-io All rights reserved. + * Copyright (C) 2012 Intel Corp. All rights reserved. + */ + +#ifndef BTRFS_RAID56_H +#define BTRFS_RAID56_H + +#include +#include +#include +#include +#include +#include +#include "volumes.h" + +struct page; +struct btrfs_fs_info; + +enum btrfs_rbio_ops { + BTRFS_RBIO_WRITE, + BTRFS_RBIO_READ_REBUILD, + BTRFS_RBIO_PARITY_SCRUB, +}; + +/* + * Overview of btrfs_raid_bio. + * + * One btrfs_raid_bio represents a full stripe of RAID56, including both data + * and P/Q stripes. For now, each data and P/Q stripe is of a fixed length (64K). + * + * One btrfs_raid_bio can have one or more bios from higher layer, covering + * part or all of the data stripes. + * + * [PAGES FROM HIGHER LAYER BIOS] + * Higher layer bios are in the btrfs_raid_bio::bio_list. + * + * Pages from the bio_list are represented like the following: + * + * bio_list: |<- Bio 1 ->| |<- Bio 2 ->| ... + * bio_paddrs: [0] [1] [2] [3] [4] [5] ... + * + * If there is a bio covering a sector (one btrfs fs block), the corresponding + * pointer in btrfs_raid_bio::bio_paddrs[] will point to the physical address + * (with the offset inside the page) of the corresponding bio. + * + * If there is no bio covering a sector, then btrfs_raid_bio::bio_paddrs[i] will + * be INVALID_PADDR. + * + * The length of each entry in bio_paddrs[] is a step (aka, min(sectorsize, PAGE_SIZE)). + * + * [PAGES FOR INTERNAL USAGES] + * Pages not covered by any bio or belonging to P/Q stripes are stored in + * btrfs_raid_bio::stripe_pages[] and stripe_paddrs[], like the following: + * + * stripe_pages: |<- Page 0 ->|<- Page 1 ->| ... + * stripe_paddrs: [0] [1] [2] [3] [4] ... + * + * stripe_pages[] array stores all the pages covering the full stripe, including + * data and P/Q pages. + * stripe_pages[0] is the first page of the first data stripe. + * stripe_pages[BTRFS_STRIPE_LEN / PAGE_SIZE] is the first page of the second + * data stripe. + * + * Some pointers inside stripe_pages[] can be NULL, e.g. for a full stripe write + * (the bio covers all data stripes) there is no need to allocate pages for + * data stripes (can grab from bio_paddrs[]). + * + * If the corresponding page of stripe_paddrs[i] is not allocated, the value of + * stripe_paddrs[i] will be INVALID_PADDR. + * + * The length of each entry in stripe_paddrs[] is a step. + * + * [LOCATING A SECTOR] + * To locate a sector for IO, we need the following info: + * + * - stripe_nr + * Starts from 0 (representing the first data stripe), ends at + * @nr_data (RAID5, P stripe) or @nr_data + 1 (RAID6, Q stripe). + * + * - sector_nr + * Starts from 0 (representing the first sector of the stripe), ends + * at BTRFS_STRIPE_LEN / sectorsize - 1. + * + * - step_nr + * A step is min(sector_size, PAGE_SIZE). + * + * Starts from 0 (representing the first step of the sector), ends + * at @sector_nsteps - 1. + * + * For most call sites they do not need to bother this parameter. + * It is for bs > ps support and only for vertical stripe related works. + * (e.g. RMW/recover) + * + * - from which array + * Whether grabbing from stripe_paddrs[] (aka, internal pages) or from the + * bio_paddrs[] (aka, from the higher layer bios). + * + * For IO, a physical address is returned, so that we can extract the page and + * the offset inside the page for IO. + * A special value INVALID_PADDR represents when the physical address is invalid, + * normally meaning there is no page allocated for the specified sector. + */ +struct btrfs_raid_bio { + struct btrfs_io_context *bioc; + + /* + * While we're doing RMW on a stripe we put it into a hash table so we + * can lock the stripe and merge more rbios into it. + */ + struct list_head hash_list; + + /* LRU list for the stripe cache */ + struct list_head stripe_cache; + + /* For scheduling work in the helper threads */ + struct work_struct work; + + /* + * bio_list and bio_list_lock are used to add more bios into the stripe + * in hopes of avoiding the full RMW + */ + struct bio_list bio_list; + spinlock_t bio_list_lock; + + /* + * Also protected by the bio_list_lock, the plug list is used by the + * plugging code to collect partial bios while plugged. The stripe + * locking code also uses it to hand off the stripe lock to the next + * pending IO. + */ + struct list_head plug_list; + + /* Flags that tell us if it is safe to merge with this bio. */ + unsigned long flags; + + /* + * Set if we're doing a parity rebuild for a read from higher up, which + * is handled differently from a parity rebuild as part of RMW. + */ + enum btrfs_rbio_ops operation; + + /* How many pages there are for the full stripe including P/Q */ + u16 nr_pages; + + /* How many sectors there are for the full stripe including P/Q */ + u16 nr_sectors; + + /* Number of data stripes (no p/q) */ + u8 nr_data; + + /* Number of all stripes (including P/Q) */ + u8 real_stripes; + + /* How many pages there are for each stripe */ + u8 stripe_npages; + + /* How many sectors there are for each stripe */ + u8 stripe_nsectors; + + /* + * How many steps there are for one sector. + * + * For bs > ps cases, it's sectorsize / PAGE_SIZE. + * For bs <= ps cases, it's always 1. + */ + u8 sector_nsteps; + + /* Stripe number that we're scrubbing */ + u8 scrubp; + + /* + * Size of all the bios in the bio_list. This helps us decide if the + * rbio maps to a full stripe or not. + */ + int bio_list_bytes; + + refcount_t refs; + + atomic_t stripes_pending; + + wait_queue_head_t io_wait; + + /* Bitmap to record which horizontal stripe has data */ + unsigned long dbitmap; + + /* Allocated with stripe_nsectors-many bits for finish_*() calls */ + unsigned long finish_pbitmap; + + /* + * These are two arrays of pointers. We allocate the rbio big enough + * to hold them both and setup their locations when the rbio is + * allocated. + */ + + /* + * Pointers to pages that we allocated for reading/writing stripes + * directly from the disk (including P/Q). + */ + struct page **stripe_pages; + + /* Pointers to the sectors in the bio_list, for faster lookup */ + phys_addr_t *bio_paddrs; + + /* Pointers to the sectors in the stripe_pages[]. */ + phys_addr_t *stripe_paddrs; + + /* Each set bit means the corresponding sector in stripe_sectors[] is uptodate. */ + unsigned long *stripe_uptodate_bitmap; + + /* Allocated with real_stripes-many pointers for finish_*() calls */ + void **finish_pointers; + + /* + * The bitmap recording where IO errors happened. + * Each bit is corresponding to one sector in either bio_sectors[] or + * stripe_sectors[] array. + */ + unsigned long *error_bitmap; + + /* + * Checksum buffer if the rbio is for data. The buffer should cover + * all data sectors (excluding P/Q sectors). + */ + u8 *csum_buf; + + /* + * Each bit represents if the corresponding sector has data csum found. + * Should only cover data sectors (excluding P/Q sectors). + */ + unsigned long *csum_bitmap; +}; + +/* + * For trace event usage only. Records useful debug info for each bio submitted + * by RAID56 to each physical device. + * + * No matter signed or not, (-1) is always the one indicating we can not grab + * the proper stripe number. + */ +struct raid56_bio_trace_info { + u64 devid; + + /* The offset inside the stripe. (<= STRIPE_LEN) */ + u32 offset; + + /* + * Stripe number. + * 0 is the first data stripe, and nr_data for P stripe, + * nr_data + 1 for Q stripe. + * >= real_stripes for + */ + u8 stripe_nr; +}; + +static inline int nr_data_stripes(const struct btrfs_chunk_map *map) +{ + return map->num_stripes - btrfs_nr_parity_stripes(map->type); +} + +static inline int nr_bioc_data_stripes(const struct btrfs_io_context *bioc) +{ + return bioc->num_stripes - btrfs_nr_parity_stripes(bioc->map_type); +} + +#define RAID5_P_STRIPE ((u64)-2) +#define RAID6_Q_STRIPE ((u64)-1) + +#define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) || \ + ((x) == RAID6_Q_STRIPE)) + +struct btrfs_device; + +void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc, + int mirror_num); +void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc); + +struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio, + struct btrfs_io_context *bioc, + struct btrfs_device *scrub_dev, + unsigned long *dbitmap, int stripe_nsectors); +void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio); + +void raid56_parity_cache_data_folios(struct btrfs_raid_bio *rbio, + void *vaddr, u64 data_logical); + +int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info); +void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info); + +#endif -- cgit v1.3.1